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Topic: Attenuation (Read 7054 times)

I use WLP001 for most of my beers. I like how clean it is and it typically makes for some good, tasty beverages. Recently, its been taking my beers down to 1.008. I like the extra abv but its leaving my beer really thin. I'm hitting mash temps, OG targets and fermenting in the mid 60's. Based on my recipes and fermentation parameters, I should be hitting 1.012-1.010.

Any tips? Raise mash temp? Add some less fermentable grains to increase body? Any help is appreciated.

I dont think its an infection as I'm not getting off flavors or other weird things going on. I've never used brett in the brewery so if some got in, it got in from the air and its not putting that dry brett flavor in my beer.I'm getting well better than 80% attenuation from this and I understood that this yeast topped out at 80%.

What temp are you mashing at? My first reaction would definitely be to raise your mash temps. I can only assume you're in the low 150 or even high 140 range. If this is the case, shoot for around 156 maybe and see what that does for you.

What temp are you mashing at? My first reaction would definitely be to raise your mash temps. I can only assume you're in the low 150 or even high 140 range. If this is the case, shoot for around 156 maybe and see what that does for you.

I've had low-level infections that caused better than expected attenuation. Certain kinds of mold can knock a couple points off without causing noticeable (to me anyway) off-flavors. FWIW I don't find that mash temp has all that big of an effect on attenuation. I think it has a lot more to do with yeast strain and ferm temp.

1.008 is about where I'd expect Chico to finish when mashing low like that. If you want an average-gravity beer to finish out closer to 1.012, you'll need to mash at about 156-158°F.

On the other hand, I'm of the firm opinion that high attenuation is the ONLY reason to use Chico. If that isn't what you want, maybe you should consider switching to something that's going to be more flocculant. Assuming you aren't filtering.

Thanks everyone! The last batch we brewed was the APA from Brewing Classic Styles. The one before that was an american wheat, also from brewing classic styles. I changed up the hops on that one but the grain bill and fermentation were kept the same. So my confusion comes from these points. The recipe called for a mash of 152. I hit my mash temp spot on and held it. The OG for this beer was 1.056 and the FG should have been 1.013. Going down to 1.008 just seems like its going too far. I was under the impression that Chico topped out at 80% attenuation. I'm starting to think there may be an infection of some sort even though there arent any off flavors making themselves noticeable. The yeast is a repitch. I split it into two pitches. Those two pitches went into my APA and the wheat which both went down to 1.008. I think I'm going to throw away the yeast that I harvested from those two batches and start over.

There's really no such thing as a yeast "topping out". The fermentability limit of the wort is set in the brewhouse, and with a low-flocculating strain like Chico, the FG should always be very near that limit.

Just for reference, our standard mash at the brewery is 153.5°F, which gives a target FG of 2.5°P given a 12°P OG. That's 79% ADF, and obviously we could mash several degrees lower to increase that. Normally, I'd suggest that you calibrate your mash thermometer, but given that your results are exactly in line with what I see 4-6 times a week, I think you are actually mashing at about 152°F, and getting the fermentability that would be expected from that mash.

I very much doubt you have a contamination issue. There just isn't enough "surplus" attenuation happening.

There's really no such thing as a yeast "topping out". The fermentability limit of the wort is set in the brewhouse, and with a low-flocculating strain like Chico, the FG should always be very near that limit.

Just for reference, our standard mash at the brewery is 153.5°F, which gives a target FG of 2.5°P given a 12°P OG. That's 79% ADF, and obviously we could mash several degrees lower to increase that. Normally, I'd suggest that you calibrate your mash thermometer, but given that your results are exactly in line with what I see 4-6 times a week, I think you are actually mashing at about 152°F, and getting the fermentability that would be expected from that mash.

I very much doubt you have a contamination issue. There just isn't enough "surplus" attenuation happening.

Thanks! I will be raising the mash temp on the next go round and see what happens. If that doesnt do it, I'll look at tweaking my recipes to add some more body from grain additions. One step at a time, right?

My only input may be impact of pitching rate since you re-pitched your yeast. I've had some variability with Chico Strain, but in big, healthy pitches it does great. My last IPA: 1.065-1.008 (87% ADF) in about 11 days (that was the first time I checked it)

My only input may be impact of pitching rate since you re-pitched your yeast. I've had some variability with Chico Strain, but in big, healthy pitches it does great. My last IPA: 1.065-1.008 (87% ADF) in about 11 days (that was the first time I checked it)

I use Mr.malty to calculate my pitching rates. For these last couple of beers the pitching rate was 150 ml of yeast for 1.056 OG. I hit the yeast with a little cooled wort from the boil kettle on brew day to wake it up before we pitch in.

My only input may be impact of pitching rate since you re-pitched your yeast. I've had some variability with Chico Strain, but in big, healthy pitches it does great. My last IPA: 1.065-1.008 (87% ADF) in about 11 days (that was the first time I checked it)

I use Mr.malty to calculate my pitching rates. For these last couple of beers the pitching rate was 150 ml of yeast for 1.056 OG. I hit the yeast with a little cooled wort from the boil kettle on brew day to wake it up before we pitch in.

Bingo. Changing only one aspect of your process at a time makes it a lot easier to isolate the issue. If you change a whole bunch of stuff and the problem gets fixed, you may be more satisfied with the final product but you really won't know why. Let us know how the next batch turns out.